Colostrum 100% Pure Powder 3 oz by NOW is a supplement made from a fluid produced naturally for infants prior to milk production and is derived from cows. It is rich in proteins such as immunoglobulins and lactoferrin. Because of this. it is used to maintain lean muscle while bolstering the immune system. Studies have also shown it to be an aid in the body's absorption of nutrients through its support of the digestive system.